FT_ARTIFACT_THRESHOLD
Note that this reference documentation is identical to the help that is displayed in MATLAB when you type “help ft_artifact_threshold”.
FT_ARTIFACT_THRESHOLD scans for trials in which the range, i.e. the minimum, the maximum or the range (min-max difference) of the signal in any channel exceeds a specified threshold. Use as [cfg, artifact] = ft_artifact_threshold(cfg) with the configuration options cfg.dataset = string with the filename or cfg.headerfile = string with the filename cfg.datafile = string with the filename and optionally cfg.headerformat cfg.dataformat Alternatively you can use it as [cfg, artifact] = ft_artifact_threshold(cfg, data) where the input data is a structure as obtained from FT_PREPROCESSING. In both cases the configuration should also contain cfg.trl = structure that defines the data segments of interest, see FT_DEFINETRIAL cfg.continuous = 'yes' or 'no' whether the file contains continuous data The following configuration options can be specified cfg.artfctdef.threshold.channel = cell-array with channel labels cfg.artfctdef.threshold.bpfilter = 'no' or 'yes' (default = 'yes') cfg.artfctdef.threshold.bpfreq = [0.3 30] cfg.artfctdef.threshold.bpfiltord = 4 It is also possible to use other filter (lpfilter, hpfilter, bsfilter, dftfilter or medianfilter) instead of a bpfilter for preprocessing, see FT_PREPROCESSING The detection of artifacts is done according to the following settings, you should specify at least one of these thresholds cfg.artfctdef.threshold.range = value in uV or T, default inf cfg.artfctdef.threshold.min = value in uV or T, default -inf cfg.artfctdef.threshold.max = value in uV or T, default inf cfg.artfctdef.threshold.onset = value in uV or T, default inf cfg.artfctdef.threshold.offset = value in uV or T, default inf When cfg.artfctdef.threshold.range is used, the within-channel peak-to-peak range is checked against the specified maximum range (so not the overall range across channels). In this case the whole trial will be marked as an artifact. When cfg.artfctdef.threshold.onset and offset are used, the rising and falling flank are thresholded with different values. In case onset and offset are both positive, the data will be thresholded above their values. In case both onset and offset are negative, the data will be thresholded below their values. Note that this function does not support artifact- or filterpadding. The output argument "artifact" is a Nx2 matrix comparable to the "trl" matrix of FT_DEFINETRIAL. The first column of which specifying the beginsamples of an artifact period, the second column contains the endsamples of the artifactperiods. To facilitate data-handling and distributed computing you can use cfg.inputfile = ... If you specify one of these (or both) the input data will be read from a *.mat file on disk and/or the output data will be written to a *.mat file. These mat files should contain only a single variable, corresponding with the input/output structure. See also FT_REJECTARTIFACT, FT_ARTIFACT_CLIP, FT_ARTIFACT_ECG, FT_ARTIFACT_EOG, FT_ARTIFACT_JUMP, FT_ARTIFACT_MUSCLE, FT_ARTIFACT_THRESHOLD, FT_ARTIFACT_ZVALUE